Field of the Invention
Embodiments of the invention generally relate to apparatuses and methods for cleaning process chambers of substrate processing apparatuses. More particularly, embodiments of the present invention relate to apparatus and methods for cleaning a process chamber used for deposition.
Description of the Related Art
After a number of deposition steps have been performed in a process chamber, the process chamber may need cleaning to remove undesirable deposition residues that may have formed on the chamber wall. One conventional approach for cleaning current chemical vapor deposition (CVD) or plasma enhanced chemical vapor deposition (PECVD) process chambers is to use cleaning plasma supplied from a remote plasma source (RPS) separate from the process chamber. The RPS provides the cleaning plasma, usually formed from a fluorine-based cleaning gas, which is flowed into the deposition chamber via gas circulation hardware comprising a gas box, gas manifold, and a gas distribution system installed in the process chamber.
To obtain a higher etching rate during cleaning, the cleaning plasma is usually supplied in an active form comprised of atomic fluorine radicals. However, complex transport paths from the RPS to the deposition chamber usually results in a premature recombination of the atomic fluorine radicals into molecular gases that have a lower etching rate. Consequently, cleaning efficiency may be low even if precursor dissociation efficiency of cleaning gases is high. Further, for chambers having large volume and intricate geometry, such as a 300 mm process chamber, the chamber pumping port is usually close to a shower head utilized to deliver cleaning gases to the chamber. Therefore, poor circulation of gases under a substrate support assembly positioned between the showerhead and pumping port results in decreased cleaning efficiency under the substrate support assembly.
Therefore, there is a need for an improved apparatus and method for cleaning a deposition chamber.